1. Technical Field
The present invention provides a pedal-ring tightening structure which comprises a pedal ring coupled to a supporting central tube of a seat at a predetermined height. At least two clamping elements are coupled to the periphery of the central tube at a predetermined height, such that a sleeve disposed centrally at the pedal ring formed peripherally and integrally with a predetermined width is coupled to the periphery of the clamping elements. A protruding portion extending from an inner rim of a fixing ring is inserted into a space concavely disposed at the upper end of each said clamping element to abut against precisely and press inward each said clamping element coupled to the periphery of the central tube, such that the pedal ring is steadily clamped and positioned at the central tube upon assembly.
2. Description of Related Art
To allow the sitter of a conventional seat to rest his or her feet at a relatively high level, a pedal ring is coupled to the periphery of a supporting central tube of the conventional seat, so that the sitter can rest his or her feet on the pedal ring comfortably. The pedal ring coupled to the periphery of the supporting central tube of the conventional seat comes in a wide variety of forms for users to select as needed.
Referring to FIG. 1, there is shown a conventional pedal ring 10 of a seat. The pedal ring 10 is made of an appropriate material and formed integrally with the periphery of a sleeve 101. The sleeve 101 coupled to the pedal ring 10 fits around a supporting central tube 30 of a seat 20. A knob 40 with a thread 401 extending from an end of the knob 40 is provided. The thread 401 of the knob 40 corresponds in position to a predefined hole of the sleeve 101. The thread 401 of the knob 40 meshes with the hole of the sleeve 101 to enable the sleeve 101 to precisely press on and abut against the supporting central tube 30 of the seat 20, such that the pedal ring 10 is precisely and firmly coupled to the supporting central tube 30 of the seat 20 at a predetermined height, thereby allowing the user to rest his or her feet on the pedal ring 10 conveniently and comfortably.
Although users rest their feet on the pedal ring 10 comfortably, the single said thread 401 is likely to slide downward when trodden. Moreover, the pedal ring 10 can be tightened and positioned as expected only when the knob 40 is turned and tightened sufficiently.